<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .button-arrow {
            padding: 10px;
            height: 12px;
            width: 12px;
            border: 1px solid #ddd;
            display: inline-block;
        }
        .button-arrow__down::before,
        .button-arrow__left::before,
        .button-arrow__right::before,
        .button-arrow__up::before {
            display: block;
            content: "";
            width: 12px;
            height: 12px;
        }
        .button-arrow__up::before {
            border-left: 1px solid #666;
            border-top: 1px solid #666;
            transform:  translateY(25%) rotate(45deg)  ;
        }
        .button-arrow__right::before {
            border-right: 1px solid rgba(0, 0, 0, 0.3);
            border-top: 1px solid rgba(0, 0, 0, 0.3);
            transform: translateX(-25%) rotate(45deg);
        }

        .button-arrow__down::before {
            border-bottom: 1px solid rgba(0, 0, 0, 0.3);
            border-right: 1px solid rgba(0, 0, 0, 0.3);
            transform: translateY(-25%) rotate(45deg);
        }
        .button-arrow__left::before {
            border-bottom: 1px solid rgba(0, 0, 0, 0.3);
            border-left: 1px solid rgba(0, 0, 0, 0.3);
            transform: translateX(25%) rotate(45deg);
        }
    </style>
</head>
<body>
     <!-- 向上箭头 -->
  <div class="button-arrow button-arrow__up"></div>
  <!-- 向右箭头 -->
  <div class="button-arrow button-arrow__right"></div>
  <!-- 向下箭头 -->
  <div class="button-arrow button-arrow__down"></div>
  <!-- 向左箭头 -->
  <div class="button-arrow button-arrow__left"></div>
</body>
</html>